Improvement in saws



S. SCHOLFIELD.

Saws.

Yund:

WITNESSES QM 5w@ f @7W IINTED STATEs SOCRATES SOHOLFIELD, OF PROVIDENCE,RHODE ISLAND.

IMPROVEMENT IN SAWS.

Specification forming part of Letters Patent No. 139,426, dated May 27,1873; application filed November 25, 1872.

To all whom it may concern;

Beit known that I, SOCRATES ScHoLErELD, of Providence, in the county ofProvidence and State of Rhode Island, have invented an Improvement inSaws for Logging, of which the following is a specification:

The nature of my invention consists in the employment of tworeciprocating saws placed side by side, and arranged to operate withinthe same kerf by being moved simultaneously in opposite directions.-Heretofore, in all attempts to fell trees and saw off logs by the use ofsteam or other power, it has been Vfound necessary to employ aframe-work whichwas required to be attached to the tree or to theground, thus rendering machines of this nature extremely liable toaccident, for the reason that in some cases it would be impossible toremove the machine out of the way of a falling tree in time to preventserious injury to the apparatus.

The necessity for the employment of the frame-work referred to arisesfrom the unbalanced action of a single saw, which in all cases requiresa fixed point outside of the sawkerf from which to base its operation.`But, instead of operating from an outside xed point, as abovementioned, I obtain the desired counter-resistance within the saw-kerfitself, by which means I am enabled to entirely dispense with thepermanent fastening or attachment to the tree, as heretofore, and cantherefore take the saw out of the kerf at any instant, when necessary,to remove the machine from danger. Either steam or compressed air may bereadily employed as the motive power for operating the saws, theprincipal require- Vment being a light and simple engine. In theaccompanying drawing the machine is represented as driven by a rotarysteam-engine of my own invention, which appears to be well adapted forthe purpose. But I also contemplate operating the saws by means oftworcciprocating pistons.

Figure lis a side view of my improved sawin g-machine and engine bywhich it is operated. Fig. 2lis a top view of the same. Fig. 3 is alongitudinal section taken in the center line. Fig. 4 is a transversesection taken in the line a: w. Fig. 5 is a transverse section taken inthe line y y.

In the drawing, A A represent two sawblades, placed side by side, andheld together loosely by means of the holding-guide B. The blades A Alare slotted at a a for the reception of the fixed guide-plate c, whichserves to retain the saws in their proper relation to the holding-guideB. The slots b b are arranged to receive the guide-plates d d', whichare rigidly attached to the `blades A A. Connection is made, by means ofthe connectiugnods .D D', between the blades A A and the cranks C C',which are placed diametrically opposite each other upon the shaft E ofthe rotary engine F. Upon the rotation of the shaft E the blades A Awill move in opposite directions, and, each having an equal hold uponthe fibers of the wood, will cause the action of one of the blades so tobalance the action of the other thattherawill be no tendency to reactupon thgjirson that holds the machine. He can therefore hold the machineand guide the saws with comparative ease and be instantly preparedincase of danger to remove the machine to a place of safety.

In operating the machine with steam, I employ a movable boiler,temporarily stationed in a suitable locality, from which the steam is tobe transmitted tothe machine through a flexible hose or pipe. I give tothe blades A A a stroke of from four to eight inches, and require theperson guiding the saws to move them back and forth in the kerf as inordinary sawing by hand. The movement of the blades in opposition toeach other will be sufficient to do the cutting, while the movementotherwise imparted by the workman is merely for the purpose ofdischarging the sawdust with greater rapidity than would be possiblewhen relying upon the action of the blades alone, owing to thecomparative shortness of their strokes and their opposite movementwithin the same kerf. On account of the additional stiffness imparted bythe holding-guide B the blades A A may be made somewhat thinner thancommon in single saws, and, in order to have them run together properlywhen placed in close contact, the `teeth should be set or deflected uponthe outer sides of the blades, as shown in Fig. 4. The machine is to befurnished with suitable handles at G G and H, in order that it may beeasily operated and controlled by the workman under all necessaryconditions.

The holding-gilide B may be constructed 3. The combination Of the saws AA with and applied to operate either'betwecu or outa holding-guide, B,shaft E, opposite cranks side of the saws. C C', and connecting-rods DD', substantially I claim as my inventionas described.

1. The combination, substantially as de- SOCRATES SCHOLFIELD. scribed,of two saws arranged side by side for y operation in the same kerf. AWitnesses:

2. The combination of the saws A Al with GEORGE H. ROGERS, a holding-guide, B, substantially as described. ALBA B. ABBOTT.

